[l889]

Hi,

I`ve a big problem with two MIRO 2193 Monitors. (both the same error)
First the Power Supply was exploded, I have repaired it, now the probem is, when I power on the monitor there is a short in it. I found out, that the regulator P-FET for the hi-voltage driver circuit was shorted, and the IGBT (1MB12-14???)-driver for the DST was shorted, too. Both parts was replaced by the original parts. If I now power on the monitor there still is a short in the HV-Generation. (The H-ABL works.) It makes "tweet, tweet" sounds, then I switch of, because the regulator P-FET will be very hot and destroyed if I don`t.
The resistance between Source and Drain of this FET is ca 500k to 1M, the resistance between the DST-main-coil ca 1,7R that`s correct, because I have three DST`s for this Screen, and they have been simulated OK.
If I put in an 100W lamp, it will blink periodly, when the sound appears. The short still exist, but I can`t find the reason. All parts checks OK.

Sorry that I`m writing english, but this forum is my last chance to get the screens working. How can I find the error??? Anybody any idea?? (I hope.... )

Thank you! L889 from germany

[DMV]

Some questions
1. Do you have any shematics or service manuals for subject or any links?
2. Please write FCCID for subject.
3. HOT(1MB12-14???) was disconnected When you put in 100W lamp or not?
4. Check inductance of B+ Coil.
5. Check waveforms of Flyback pulse - may be FBT bad.

[l889]

Some questions
1: No, I`ve no schema... ;-(
2: can`t find any FCC ID... MIRO 21
-> Miro C2193 (Mitsubishi Chassis)
-> equivalent to: Mitsubishi THN 9175
3: no, the HV-Driver was connected. Without it, there was no light... The HOT is another transistor, i think 2SC5???
4: ...later
5: FBT is OK! I`ve checked other FBT`s of the same type, and the error is still there.

There is a little SMD board on the main board. It`s the HV-Controller + X-Ray circuit. I think this board (there are two opamps on it) is defect. I`ll try to rebuild it. (If I switch on the Screen without this SMD-Board the error isn`t there...)